The reforming of petroleum hydrocarbon streams is one of the important petroleum refining processes that may be employed to provide high-octane number hydrocarbon blending components for gasoline. In the typical reforming process, the reactions comprise dehydrogenation reactions, isomerization reactions, and hydrocracking reactions. The dehydrogenation reactions include the dehydrogenation of cyclohexanes to aromatics, the dehydroisomerization of alkylcyclopentanes to aromatics, the dehydrogenation of paraffins to olefins, and the dehydrocyclization of paraffins and olefins to aromatics. The isomerization reactions include isomerization of n-paraffins to isoparaffins, the hydroisomerization of olefins to isoparaffins, the isomerization of alkylcyclopentanes to cyclohexanes, and the isomerization of substituted aromatics. The hydrocracking reactions include hydrocracking of paraffins and hydrodesulfurization. Adequate discussions of the reactions occurring in a reforming reaction zone are presented in CATALYSTS, Vol. VI, P. H. Emmett, editor, Reinhold Publishing Corporation, 1958, pages 497-498, and PETROLEUM PROCESSING, R. J. Hengstebeck, McGraw-Hill Book Company, Inc., 1959, pages 179-184.
It is well-known by those skilled in the art that several catalysts are capable of reforming petroleum naphthas and hydrocarbons that boil in the gasoline boiling range. Although reforming may be carried out through the use of molybdena-on-alumina catalysts, chromium-oxide-on-alumina catalysts, platinum-halogen-on-alumina catalysts, and platinum-aluminosilicate-material-alumina catalysts, the catalysts employing platinum as a hydrogenation component are generally employed today in the reforming processes of the petroleum industry.
Finely-divided crystalline aluminosilicate material can be used as a component in a catalyst that is employed for the reforming of hydrocarbon streams. For example, Bertolacini in U.S. Pat. No. 3,546,102, Bertolacini, et al., in U.S. Pat. No. 3,376,214, and Bertolacini, et al., in U.S. Pat. No. 3,376,215 teach the use of catalysts comprising a Group VIII noble metal and a solid support of crystalline mordenite-structure aluminosilicate material and an adsorbent refractory inorganic oxide, such as alumina, for the reforming of hydrocarbon streams. Moreover, in U.S. Pat. No. 4,325,808, Kim, et al., teach a hydrocarbon conversion catalyst system comprising a mixture of a first catalytic material containing a noble metal component deposed on a refractory inorganic oxide which is free of a crystalline aluminosilicate material and a second catalyst comprising at least one non-noble metal component deposed on a solid support comprising a cation-exchanged crystalline aluminosilicate material dispersed in a high surface area, porous refractory inorganic oxide and being free of a noble metal component. The crystalline aluminosilicate material can be natural or synthetic and can be suitably mordenite, faujasite, or ferrierite. Kim, et al., teach that such catalyst is suitable for the reforming of petroleum hydrocarbons. In U.S. Pat. No. 4,269,813, Klotz discloses crystalline borosilicates, their method of preparation, and their use to catalyze various processes, including isomerization, disproportionation, transalkylation, and reforming of hydrocarbon streams.
It is known that catalysts comprising physical particle-form mixtures of two or more components can be used to reform hydrocarbon streams, as shown in U.S. Pat. No. 4,302,358 by Pellet, et al., in U.S. Pat. No. 4,141,859, by Plank, et al., and in the above-discussed U.S. Pat. No. 4,325,808, by Kim, et al. In U.S. Pat. No. 4,302,358, Pellet, et al., disclose a catalyst comprising a physical particle-form mixture of a Component A and a Component B, wherein Component A comprises at least one Group VIII noble metal deposed on a solid catayst support material providing acidic catalytic sites and said Component B comprises rhenium or a compound of rhenium deposed on a solid catalyst support material, said catalysts having been prepared by thoroughly blending finely-divided particles having a particle diameter that is less than 100 mesh (150 microns), and forming the composite in particles having a size that is greater than 100 mesh (150 microns) and that such catalyst is suitable for the reforming of hydrocarbon streams. In U.S. Pat. No. 4,141,859, Plank, et al., disclose that a catalyst made up of a mixture of a conventional reforming catalyst and a crystalline aluminosilicate zeolite can be used as the second catalyst in a two-catalyst reforming system, that the catalyst can have as its molecular sieve component a member selected from the group consisting of ZSM-5, ZSM-35, and a mordenite-structure aluminosilicate material, and that the catalyst can be a physical particle-form mixture of the conventional reforming catalyst (platinum, rhenium, and combined halogen on an alumina support) and the crystalline aluminosilicate zeolite.
Now there has been found a catalyst comprising a physical particle-form mixture of a Component A comprising at least one Group VIII noble metal deposed on a solid catalyst support material providing acidic catalytic sites and a Component B comprising a crystalline borosilicate material and reforming processes employing such a catalyst; in particular, a reforming process wherein such catalyst is the second catalyst in a two-catalyst system.